05 Rumble Bee 5.7 4x4 11 to 13 around town, put you foot into it 9 to 10[:@]

 

I have a 2006 with the MDS Hemi. I have filled the truck up 3 times. Each time I have done the ol pen and paper mathmatics to compare with the overhead console. Each time I have been about .8 to 1 mpg different than the overhead console. I have reset the overhead as soon as the tank is full and truck is started for the first time. I have been getting around 14.6 by overhead and 13.5 pen and paper. The first two tanks were with 87 but this last tank is with 89. Trying to see if the owners manual recommended fuel will help any. I drive mostly in town. My work is only 3 miles from my house with the speed limit never above 35mph.

 

I just did a 140 mile trip (West to East with the wind) and averaged 20.6 mpg on the high way at 75mph with the cruise set. I did minimal drafting of cars in front of me. I was getting about 18+ before my recent mods. Recently I installed a 50 series flowmaster, and a electric fan. I also just changed my axles to Royal Purple, but I don't think the axle lube has a big affect. I'm hoping I will hit above 21mpg after I install my underdrive pulley. I also have a CAI, and was not pulling a load.

 

Motor, but was that reading the overhead? I want pen and paper numbers. Your 140 mile stretch can say one thing, but what I want to know overall, after a fill up, how many miles did you go after that?

 

I filled up just before the trip and right afterwards. That was pen and paper math. The overhead said 20.4mpg. Lately the overhead computer has been pretty accurate. Only the first few thousand miles (when I bought the truck) was it off. And it has never been off more than 0.8 mpg. I can be pretty light on the throttle when I want the numbers high. My stepdad tought me to drive, and he works at the Chrysler Provng Grounds doing fuel economy tests. So you can guess how well I can steady my foot. The biggestt key is when to accelerate and when to coast. When I accelerate on the highway, I almost never let the transmission downshift, which reallys helps. It only takes one split second jump on the throttle to make the mpg's drop significantly. I'm taking another trip this weekend. It should be about 600 miles round trip, so we'll see what I can come up with for fuel economy.

 

Cool, thanks.

 

'04 1500 QCSB Hemi, 3.55, 105k miles, bone stock. So far 11-12 in town and 15-17 highway on the overhead. I've only had 1 tank so far and with pen and paper averaged 12.9 with 70/30 city/ hiway driving.

 

lerouxma,
Got a few Questions,

What did you do to your MDS Hemi to get that 26 - 28 MPG.
did you use cruise control? Do you have and after mkt air filter?
Did you have a Cat Back Exhause sytem?
And any other thing? How many miles on it?

I have a new one also with 17 ' tires only 500 miles though.
Have not been on the roooad yet!
I'm tying to see what I have to do to get better than the published MPG

Thanks very much.
"now living easily"

 

Well I didn't get my underdrive pulley on like I had planned, but I did get some fuel economy numbes I liked. We drove from Detroit to Mackinac City (300 miles) and saw 19+ mpg. This also included rush hour traffic in Detroit, so I'm happy with that. After the 300 miles was about 50 miles of around town driving that brought the numbers down to 17.8 mpg. On the way home it was very windy, and of course I was heading right into it. The final average after 460 miles was 17mpg (pen and paper). The overhead computer read 17.5mpg. I only put another 150 miles on til we got home, and heading into the wind the rest of the trip only gave me 17.7 mpg on the overhead. So 19 mpg on the way there, with a lot of up-hill grades was good enough for me. Spec's for the truck is 2005, Quad Cab, 4x4, Hemi and 3.55 gears (stock 17" tires).

 

Two weeks ago while driving down to the beach I stopped by my usual Sunoco Station to get gasoline for my boat ,I use the outboard 6 gallon tanks. So I got 12 gallons of 89 octane.$3.08 a gallon. I put ten gallons in my boat and the other two gallons in my truck. I also decided to put in a bottle of STP Fuel Injector cleaner at the same time. I reset the computer and pulled the boat to the docks and back. and then drove home. When I got home the computer said 17.2 No way could this be right. So I went to my usual Sunoco Station and filled up thew truck and the gallons used came out to 17.3 So this week I drove around a lot and Just before leaving I topped off my tank and the computer was saying 17.0 So we did the paper work and it came out to 17.2 So I guess we need a little cleaner once in a while.My tank is 26 gallons and the cleaner is set for 21 gallons. The truck is a 04 ThunderRoad Hemi, 4x4 Quad Cab.With the tow Package. Lest then 15,000 miles on it.